Draft calculator



2 Sheets-Sheet 1 F. J. LLANSO DRAFT CALCULATOR Filed Jan. 1, 1947 March 27, 1951 INVENTOR. FRANCISCO J. LLANEO A TTOEA/[Kf F. J. LLANSO DRAFT CALCULATOR March 27, 1951 2 Sheets-Sheet 2 Filed Jan. 1, 1947 1 U Iii: a; f

INVENTOR.

flQANC/fiCO J. ALA/V50 ATTOQ/VEYS Patented Mar. 27, 1951 UNITED STATES PATENT OFFICE DRAFT GALCULATQB Francisco J. "Llanso, WeS'tWOOIL "N. J;

.Apnl ca ionJnly 1,; 947LSerialN9- 75 363 9 Claims. 1

This invention relates to adevice which will predict, determine, or .control the fore and aft drafts of any ship afloat, and is intended .for use inconnection with the easyand accuratedeten mination of drafts of ships, Specifically, this .invention relates to improvements in existing instrumentsof this type.

At the present time, it is seldom that accurate predetermination of a ships draft is figured by operating personnel xchiefly because it involves lengthy mathematicalcalculations orrequires expensive and delicateinstruments. Howevensuch data are importan be ause upon it depend the ellicient operation of the ship 5856 'n l i ation through channels and into harbors of knowneu and p per s a V-k epin qualitie M r over,a proper,determination of foreand aft drafts is frequentlyrequired in repair Work as well as salvage operations.

:It: is an object of this invention. to provide a rugged and simple device for the determination or .GDIILI'Ql-Ofwllhfi flotation drafts of vessels.

Afurther object-is toprovide a device that is:

Qther ;obiects will ecome apparen in th course of the following ,=specification-.-

;In :the attainment of these objectives, two

templates, hereinafter "designated the deaf-t change template or set of parallel calibrated sca es and theyinboard profile template are-us along with .twowcoacting draft indicating tapes The draft change template or set of parallel ocalibratedscales has marked upon it in vertical geolumns a graphical representations of the+to,taldrafit change in hundreds of tons and subdivisions thereof occurring when a given weight is loaded onldischareed ate QQrreIa V cQLumna position Based upon the displacement curves Qf'tjhe Shihis design the spaoingibetween the columnar indicia in each column will vary-so that-whenever the weight represented by -a segment of the column, for example= /;..inch, is suffieientto cause achange c ftdraiflt, thespacing-between thelindiciawillhave increased loyl/ inch; Bhus, the parallel seales in he lcolumns of th draft c an e re r spectively calibrated in terms of predeterminedloads eat calibrated intervals along the scales representative of thedisplacementto the same sca assthe e fe ti d a t c an -rep sen e y the len th of th olumn al n thi l n .i ero- Whenever a column indicates va draftl change at the ioreend,

; the fig es -.d.eho i is tonnag wi in h t: co umn are in Arabic numerals, wherever the draft change s a t h fi ures a e inhuman hum ta s- Th sh ps inboa d profi e template is a d ce in schematic fo m o the ship pr fi e on which are drawn the-cargo compartments, storerooms and the like for which when a weight added to or removed therefrom zthe lchan ge oi h hipi draft may b .de ire Each se tion of such space which is representedson-tthe dratt chan t plat o pa allel cali rated cu v -hr a draft change column ,is marked-on the inboard profile template by solid vertical lines when the edge of the draft change column also marks the forward :or after Yerticalhoundary ot a .;cornpartment or by dashed vertical lines when the edge- The two dra t indicating apes c nstr cted-Qt non-stretching 1fabric material or the like are endlesstapes adaptedlto showdirectly the actual, chancel-in th ,s iprsdraft when u ed n eoni nc tion with the previously mentioned templates as shown later. Feet and inchesof ships drafit are arked-at A nchlintervals al n h edges o th -tapes swine-a ran e of draft b tween 9 and 21ifeet alongtone edgeandjirom-2 1tp 33 lee-talong th oonosite edge. vA abicnum ralsindi ate the chang in d aft vatth vform-11d and lRoma th changeiaft.

The draft :changetemplate or set of parallel calibrated scales is 1mQ1lh-tfid (on aflat base 'with its vertical columns parallelgto the longitudinal:

c nterilinaof lba e. Thainboer p ofile chart amountedena sl dab e suppo t with itsshipi at on desi n t n u de he ppropriat umn in the tonnage=draf t-change template .or

set 10f n rall calibrated sca es o wh h itmoveszlongitudinally. Ihewdrafitindicating'tapes are mounted on eitherside of the ,base .of the draft change template (and are adapted an bemoved with the slidable inboard profile template.

When determining the resulting draft arising from change of load, the draft indicating tapes are set at the designated draft marks prior to making the change. The inboard profile template is then moved up, if loading forward is the problem, to the designated tonnage in the draft change template indicated in the column above the location in which the loading is to take place. The draft indicating tape with the Arabic numerals is then pressed betwen the thumb and the slidable inboard profile chart and the draft indicating tape pulled back until the top edge of the inboard profile template is over the No draft change line. The new reading on the tape at that line will be the new draft for the fore end under the new loading plan. Since every change in distribution of load in general changes the draft of both ends of the ship, to obtain the change of draft at the aft end, the inboard profile template, dependent upon the location, is moved down to the tonnage in the appropriate column showing the change of drafts in the aft end. By pressing the draft indicating tape with the Roman numerals with the thumb against the inboard profile chart, the tape is moved up to the No draft change line and the resulting figure on the tape will show the aft draft of the ship under the new load. Knowing the new fore and aft draft figures, the mean can readily be determined.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawing showing by way of example a preferred embodiment of the inventive idea.

In the drawings:

Figure 1 is a top plan view of the device for determining the draft of a floating ship under any load constructed in accordance with the principles of this invention.

Figure 2 is an end view of the device shown in Figure 1.

Figure 3 is aside view of the device shown in Fi u e;

- Figure 4 is aviewin perspective of the device shown in Figure 1. 7 I 7 Referring now in greater detail to the drawings in which like reference numerals indicate like parts, reference numeral 10 (Figs. 1 and 4) indicates the device for determining the draft of a floating ship under any load, H the draft change template or set of parallel calibrated The'draft change template or set of parallel calibrated scales H may be made of plastic material, paper, or the like suitable for imprinting legible symbols and linesas hereinafter described. The template I l is ruled off into the vertical c01 umns [5 (Fig. 1), and the horizontal No draft change line IS. The columns have marked upon them the effect of change of draft in hundreds of tons and subdivisions thereof. The space between the columnar indicia in each column varies so that whenever the weight represented by a segment of the column is sufficient to cause an actual change of draft of, for example, 1 inch, the spacing of the columnar indicia will increase by A inch. Thus, the parallel scales in columns [5 of the draft change template H are respectively calibrated in terms of predetermined loads at calibrated intervals along the scales representative of the displacement, to the same scale as the draft change tapes l3 and [4, caused at the related end of the ship. There are sumcient colunms l5 drawn on the template ll so that each major cargo compartment, storeroom, tank, and the like or subdivision thereof is represented by a column. The number of columns is a variable dependent upon the vessel. Along the No draft change line [6 the result of draft change represented by the spacing of the indicia is zero. Whenever a column indicates a draft change at the fore end, the figures denoting tonnage within the columns are given in Arabic numerals, and whenever the change is at the aft end of the ship the numerals are Roman. In actual practice, all figures may be in Arabic and colors such as red and blue used to distinguish between fore and aft changes. It will be noted that on the draft change template I l, the Arabic numerals at the top right of the sheet are separated from the Roman numerals at the bottom by the No draft change line l6. At the left top of the template I i, it will be noted the graduations are in Roman numerals with Arabic numerals in the lower left corner. It will be further noted that approximately in the center of the sheet, both Arabic and Roman numerals are inserted above the No draft change line 16. The reason for the system adopted arises from the fact that at least in the fore and aft ends of the ship adding or subtracting weights has an opposite directional influence while approximately in the center the influence is in the same direction.

The draft change chart or set of parallel callbrated curves II is removably mounted on the base I! which may be a drawing board or the like. The right angle supports 18 serve to hold the template ll substantially parallel to the longitudinal center line of the base IT.

The ships inboard profile template [2 may be a scaled down drawing of the ships actual inboard profile but for all practical purposes may be a longitudinal sectional view of the ship in which distances between bulkhead forming the fore and aft transverse margins of the cargo holds and the like are equal throughout the ship. In Figure 1, the inboard profile chart I2, is divided into the compartments l, 2, 3, 4, 5, 6, and

I, and each of the compartments divided into three equal parts as, for example, I9, 20, and 2| (Fig. 1). It has been found convenient to form the inboard profile template [2 of opaque white plastic which may be ground so that soft penciled figures may be written thereon and erased when operating the device as subsequently shown. The inboard profile template I2 is permanent for anygiven type ship.

The inboard profile template I2 is mounted in the sliding rule 22 with the upper edge 23 thereof approximately coinciding with the upper edge of the sliding' rule 22 and its perpendicular divi sional lines 24, 25, and the like aligned with the divisional lines of the previously described col-' umns I5 of the draft'chang e chart II. Right angle supports 26 retain the template I2 in proper alignment and permits interchangeability at the users will.

The drawer 32 is provided for storing templates when not in use.

The T members 21 are attached at either end of the sliding rule l2 and are adapted to move longitudinally along the tracks 28 on either side of' the board to keep the rule 22 approximately at right angles to the longitudinal center line of the draft change template I I over which it moves;

'Ihedra-ft indicating tape 1 3 for the -fore end of the ship and 1-4 for the aft end thereof are non-stretchable endless tapes of plastic, steel, or the like adapted to move over the guides 29 mounted along the top and bottom edges alongside'the tracks 28. The guides 29 are half cylindrlcal' sections with retaining flanges 30 and 31 at either side as shown in Figure '4 to prevent the tapes l3 and M. from slipping off when pulled therearound. lhe guides '29, it will be noted, sufficiently elevate the tapes l3 and M from the planes of both the base Hand the plane of the sliding rule 22' as to be free to be pulled around theguides 28 over the top surface portion of the sliding rule 22. The tapes are marked from 9 tom along one edge with feet-inch markings. of draft, each inch of :draft: on the. tape being spaced, for example, My apart. At thezl' mark draft shifts to the opposite edge. of the tape andprogresses to 133' of draft. in this way the length of the tape is used'twice. .As-in the case of the draft change template lil, it is expected wtkatithefeet-inch markings will .be in color, draft indicating tape [3 in that color corresponding toithe fore end of the ship and draft indicating tape 14. in that color representative of the aft end 'ofither-shi-p. In Figures 1 and 4, Arabic .numerals have been used to indicate "the divisions along the edges of the tape l3, and Roman numerals the divisions along the edges of. the. tape ll. The operation is asfollows: Assuming that the proper draft change template H, and inboard profile template ['2- have been properly prepared for the ship under study and, that the present draft of the, ship at the fore end is 23 feet 1.5 inches, aft 25 feet 3 inches and it is desired to know the new draft fore and aft by adding 200 tons in the fore compartment of hold No. l and unloading 200 tons from the aft compartment of hold No. '7. Pressing the draft change tape IS with the thumb against the sliding rule 22, pull the tape i3 around the supports 29 until the reading of the tape I 3 along the No. draft change line lii is 23 feet 1.5 inches. Preferred practice requires that the draft indicating tapes always be. moved in the manner stated. Move the draft indicatingftape 'M' in -the same manner until the readin shows the assumed present draft of 25 feet 3 inches. Move the slidingrule 22 upward tofthe. 'top dotted position shown in .Figure .1 when'the upper edge will cut through the Arabic number 2 aligned with "the forward compartment of hold No. 1 on the ships inboard profile. template 12. Press the fore draft. indicating tape I3 with the thumb and drag is back along with rule 22 to the No draft change line [6, the new reading on the tape at that line will be the new fore draft of the ship by adding 200 tons at the location given. However, the aft end of the ship is also influenced and to find the magnitude pull the sliding rule 22 below the No draft change line It until the top edge thereof cuts through the Roman 11 in the column aligned with the forward section of the No. 1 hold. Press the thumb against the draft change indicating tape I4 and pull it up, using the sliding rule 22, until the top edge of the rule is again over the No draft change line IS. The new reading will show the new draft aft by loading 200 tons as indicated. If the mean should be desired, it may readily be calculated. Removing 200 tons from the aft compartment of hold No. 7, involves the opposite procedure. With the upper edge of the sliding rule 22 over the No draft change line,

6, press the tape H thereagainst and move the two members upwardly until the upper edg :of sliding rule 22 or template intersects the Roman II of the columnarscale corresponding to the aft compartment or hold No. '7. The intersection of the No draft change line with the tape M moved to the new position will give the aft draft after loading 200 tons in hold No. 1 as previously explained and removing 200 tons from hold No. "7. To obtain the fore draft under the 'removed load, press the draft tape 13 against the rule or template I2 when the upper edge of the latter is over the No draft change line and pull the two members downwardly until the upper edge of the rule or template l2 intersects the Arabic 2 in the column corresponding to the aft compartment of hold No. 7 and below the No draft changeli-ne. The intersection of the No draft change line" with the tape l3 in the new position will give the fore draft of the ship under the cumulative effect of adding 260 tons to hold No. 1 in the fore of the ship and removing 200 tons from hold No. 7 at the aft.

In this way any number of weights can :be handled in acontin-uous operation, supplying the user with a running account of the new fore and aft drafts being obtained. The device accumulates as it is operated providing a total indication at any time that the operator stops adding or subtracting weights to or from the ship. The permanent working parts of the device cause it' to have wide application and can be made adaptable to any size or type of ship by the addition of simple templates characteristic of any particular ship. A ships oiiicer, concerned with one ship, may require only one set of templates. On the other hand, a port captain, stevedor'ing superintendent, or salvage chief may require tem-- plates suitable for several ships.

It is apparent the specific illustrations above shown have been given by way of illustration and no't'by way of limitation and that the structures above described subject to wide variation and modification'without departing from the scope-or intent of the invention all of which variations and modifications are to be included Wlthin the scope of 'thepresent invention.

What is claimed is:

'1'. A device for indicating the draft of a ship under various loads in various positions, the device comprising a rectangular base member, a' set of rectangular columnar scales supported by the base member, the scales being calibrated above and below a fixed line perpendicular to the scales inaccordance with the displacement curves of the ships design, means removably attaching the columnar scales to the base member with the columns parallel to the longitudinal edges thereof; an inboard profile template coacting with the columnar scales, and having lines thereon transversely dividing it to coact with the columnar scales, a slide carrying the template for sliding it over the scales parallel to the columns thereof with the transverse divisions superposed over the coacting columnar scales; two draft indicating tapes coacting with the scales and template slide, the tapes being in the form of endless belts and having draft scale indicia thereon correlated with the columnar scales, means slidably mounting one tape along one longitudinal edge of the base and over the template slide and the other along the opposite edge and over the template slide.

2. A device for indicating the draft of a ship under various loads in various positions according to claim 1 in which the means removably attaching the columnar scales to the base member comprises at least one right angle bracket disposed on the base member with the edges of the bracket parallel to adjacent edges of the base member and adapted for the releasable insertion of one corner of the set of rectangular calibrated scales.

3. A device for indicating the draft of a ship under various loads in various positions according to claim 1 in which the slide comprises means releasably attaching the template along the upper edge of the slide with the lines thereof aligned with the columnar scales.

4. A device for indicating the draft of a ship under various loads in various positions according a claim 1 comprising a member disposed on one end of the template slide and adapted to maintain the longitudinal edges of the template perpendicular to the longitudinal edges of the base member.

5. A device for indicating the draft of a ship under various loads in various positions according to claim 1 in which the means slidably mount ing one tape along one longitudinal edge of the base and over the template slide and the other along the opposite edge and over the template slide comprises guides substantially in the form of half cylindrical sections disposed along the transverse edges of the base member at the corners and with the cylindrical portion of each turned outwardly.

6. A device for indicating the draft of a ship under various loads in various positions according to claim 5 in which the base member is characterized by having supports disposed on the bottom surface portion thereof whereby the draft indicating tapes may be moved freely around the guides.

'7. A device for indicating the draft of a ship under various loads in various loading positions, the device comprising a set of columnar scales, the scales on one side being calibrated above a common zero index line transverse to the scales in accordanc with predetermined loads at intervals representative of displacement in the fore draft in various fore positions of said ship and below the index line on the same side of the columnar scales in accordance with the same loads at intervals representative of displacement in the aft draft in the same fore positions; the scales being further divided above the index line on the opposite side in accordance with predetermined loads at intervals representative of displacement in the aft draft in various aft positions of said ship and below the index line on the same side of the scales in accordance with the same loads at intervals representative of dlS'. placement in the fore draft in the same aft positions, the device further comprising a base member supporting the columnar scales, a draft indicating tape for each side of the columnar scales and coacting therewith, the tapes having draft change indicia thereon on the same scale as said columnar scales, means supporting the tapes on the base member for movement parallel to the columnar scales, and means regulating the movements of the draft tapes in accordance with selected positions on the columnar draft scales.

8. A device for indicating the draft of a ship under various loads in various loading positions according to claim 7 in which the columnar scales above the index line on one side of the scalesv correlated with known changes in the fore draft under various loads in various fore positions of the ship are characterized by having Arabic numerals at each major division of the columnar scales above the index line and Roman numerals at each major division below said line on the same side of the scales; and further characterized by having Roman numerals at each major division above the index line on the opposite side of the scales and Arabic numerals at each major division below the index line on said opposite side of the scales.

9. A device for indicating the .draft of a ship under various loads in various loading positions according to claim 7 in which the columnar scales indicating the changes in the fore and aft drafts of the ship are characterized by being color coded; and further characterized by having the correlated draft indicating tapes similarly color coded.

FRANCISCO J. LLANso.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain Apr. 11, 1929 

